kmem_map too small, revisited (5.2.1-REL-p1) [PATCH]

[Matthias Schuendehuette]

On Friday 14 May 2004 17:02, Thomas Quinot wrote:
> * Kris Kennaway, 2004-05-12 :
> > AFAIK it's just poorly chosen defaults on large memory machines.
> > Setting VM_KMEM_SIZE_MAX=419430400 fixes it for me on 3 4GB
> > machines.
>
> Thanks Kris, I've installed a new kernel with that option, I'll see
> if the symptom fails to reproduce. :-)

Well, I had this problem today as well with Soft Updates on a 
5.2.1-RELEASE-p8 machine with 2GB RAM... 

I really *like* these mail archives... ;-)

Anyway - I tried to write that down into NOTES ( since 'documenting 
these undocumented options for linting is not considered an 
affront.' :-)

------------8><-----------------

--- sys/i386/conf/NOTES.orig	Thu Jun 10 20:29:53 2004
+++ sys/i386/conf/NOTES	Thu Jun 10 20:42:55 2004
@@ -1034,6 +1034,16 @@
 
 options 	KSTACK_PAGES=3
 
+# min(max(VM_KMEM_SIZE, Physical memory/VM_KMEM_SIZE_SCALE),
+# VM_KMEM_SIZE_MAX) is the total KVA space allocated for
+# kmem_map. E.g. used by Soft Updates.
+# For large memory machines (> 1GB RAM) VM_KMEM_SIZE_MAX should
+# be set to at least 400M.
+
+options 	VM_KMEM_SIZE=(12*1024*1024)	    # 12 MB
+options 	VM_KMEM_SIZE_MAX=(200*1024*1024)    # 200 MB
+options 	VM_KMEM_SIZE_SCALE=(3)		    # 1/3 RAM
+
 #####################################################################
 
 # More undocumented options for linting.
@@ -1056,6 +1066,3 @@
 
 options 	TIMER_FREQ=((14318182+6)/12)
 
-options 	VM_KMEM_SIZE
-options 	VM_KMEM_SIZE_MAX
-options 	VM_KMEM_SIZE_SCALE

------------8><-----------------

Perhaps someone likes to commit it ...
-- 
Ciao/BSD - Matthias

Matthias Schuendehuette	<msch [at] snafu.de>, Berlin (Germany)
PGP-Key at <pgp.mit.edu> and <wwwkeys.de.pgp.net> ID: 0xDDFB0A5F